Pr0.5Ca0.5MnO3/Si异质结输运特性和整流特性研究

利用固相反应法制备Pr_0.5Ca_0.5MnO₃(PCMO)靶材,并采用脉冲激光沉积法(PLD)在n型Si(111)基片上沉积PCMO外延薄膜,研究了薄膜的输运特性及薄膜与Si衬底形成异质结的整流特性.结果表明:在80—300 K温度范围内,PCMO薄膜的阻温关系符合变程跳跃模型,随着温度的升高表现出从一维到二维再到三维的转变,分析认为可能源于轨道自由度对电子输运特性的影响.PCMO/Si异质结在磁场作用下整流特性得到改善,且在正向电流方向出 关键词： 0.5Ca_0.5MnO₃')" href="#">Pr_0.5Ca_0.5MnO₃ Si 整流 正磁电阻

Transport and rectification properties of Pr0.5Ca0.5MnO3/Si heterojunction

Pr_0.5Ca_0.5MnO₃(PCMO) is been prepared by a solid-state reaction technique, and the thin film of PCMO is deposited on an n-type silicon substrate by a pulsed laser deposition method. Experimental results indicate the transport character of the film may be consistent with the variable range hopping model in a temperature range of 80—300 K, but it changes from one-dimension to two-dimensional and then turns three-dimensional with temperature increasing. It may be attributed to the effect of orbit order on the transport characteristics. The PCMO/Si heterojunction possesses good rectifieation property under a magnetic field,and at a positive voltage the heterojunction shows its magnetoresistance to have a remarkable transition from positive to negative.